defining the relationship between encumbered ensembles and ... ·...

Defence Research andDevelopment Canada

Recherche et developpementpour la defense Canada

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Defining the relationship between encumberedensembles and task performance indiving operationsA pilot study

Allan KeefeTiffany LimDRDC – Toronto Research Centre

Defence Research and Development CanadaScientific ReportDRDC-RDDC-2018-R165June 2018

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CAN UNCLASSIFIED

IMPORTANT INFORMATIVE STATEMENTS

This document was reviewed for Controlled Goods by DRDC using the Schedule to the Defence Production Act.

Disclaimer: Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence (“Canada”), makes norepresentations or warranties, express or implied, of any kind whatsoever, and assumes no liability for the accuracy, reliability,completeness, currency or usefulness of any information, product, process or material included in this document. Nothing in thisdocument should be interpreted as an endorsement for the specific use of any tool, technique or process examined in it. Anyreliance on, or use of, any information, product, process or material included in this document is at the sole risk of the person sousing it or relying on it. Canada does not assume any liability in respect of any damages or losses arising out of or in connectionwith the use of, or reliance on, any information, product, process or material included in this document.

Endorsement statement: This publication has been peer-reviewed and published by the Editorial Office of Defence Research andDevelopment Canada, an agency of the Department of National Defence of Canada. Inquiries can be sent to:[email protected].

The data collected as part of this study was approved either by Defence Research and Development Canada’s Human ResearchEthics Board or by the Director General Military Personnel Research & Analysis’ Social Science Research Review Board.

c⃝ Her Majesty the Queen in Right of Canada, Department of National Defence, 2018

c⃝ Sa Majesté la Reine en droit du Canada, Ministère de la Défense nationale, 2018

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Abstract

DRDC’s Experimental Diving and Undersea Group (EDU) recognizes the requirement fora capability to perform sound human factors and ergonomic research to support the speci-fication, design, development, and evaluation of diving clothing, equipment and platforms.In order to leverage the emerging tools and capabilities available through DRDC’s Com-prehensive Ergonomics-based Tools and Techniques (CETTs) capabilities, a pilot studywas conducted to evaluate the effect of ensemble encumbrance on diver underwater taskperformance.

Five Royal Canadian Navy Reserve divers were recruited from the HMCS York to partici-pate in this study. Each diver participated in three dive encumbrance conditions consistingof either a a) 6mm thick wetsuit, b) Fusion dry suit or c) Kodiak dry suit. An AGA fullface dive mask and Compressed Air Breathing Apparatus (CABA) tanks were worn in eachcondition. Dive ensemble encumbrance was quantified by obtaining 3D volumetric scans,and measuring field of view and cervical range of motion. In-water assessment of ensembleencumbrance consisted of whole-body range of motion activities.

Performance tasks were based on simulated mine counter measures tasks and consistedof fine motor (rope tying and nuts/bolts assembly), gross motor (weight transfer) and avisual search tasks. All in-water tasks were recorded using waterproof GoProTM camerasand evaluated according to time to task completion, NASA TLX response and subjectivequestionnaire. Despite the low number of participants, results indicated trends that wereconsistent with task performance being adversely affected by encumbrance, as defined bya reduced range of motion. The exception was the nuts and bolts task which appeared tobenefit by the extra stability provided by a more restrictive suit. This research reinforcesthe importance of identifying objective measures of encumbrance that are relevant to divertask performance. Challenges to quantifying dive ensemble encumbrance in an underwa-ter environment are identified and research gaps, tools, resources and facilities to supportadvanced diving human factors research are identified.

Significance for defence and security

This report describes the results of a pilot study to apply novel ergonomics-based tools,equipment and methods to evaluate the underwater performance of divers performing sim-ulated mine-counter measures tasks. The results of this study can be used to inform futurehuman factors and physical ergonomics research to support the specification, design, de-velopment and evaluation of clothing, equipment and platforms used in diving operations.Additional recommendations are made to identify research gaps, tools, resources and facil-ities to support advanced diving human factors research.

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Résumé

Le Groupe de l’unité de plongée expérimentale (GPE) de RDDC reconnaît la nécessitéde posséder la capacité d’effectuer des recherches approfondies sur les facteurs humains etl’ergonomie pour appuyer la description, la conception, la mise au point et l’évaluation desvêtements, de l’équipement et des plateformes de plongée. Afin de tirer profit des capacitéset des outils émergents qu’offre l’ensemble exhaustif d’outils et de techniques ergonomiques(EEOTE) de RDDC, on a mené une étude pilote dans le but d’évaluer l’effet de la chargeexercée par l’équipement sur l’efficacité des tâches effectuées sous l’eau par les plongeurs

On a recruté cinq plongeurs de la Marine royale canadienne (Réserve) parmi l’équipagedu NCSM York pour participer à l’étude. Chaque plongeur a pris part à trois exercicesselon différentes charges de plongée, à savoir : a) une combinaison humide de 6 mm ; b)une combinaison étanche Fusion ; c) une combinaison étanche Kodiak. Tous les plongeursétaient équipés d’un masque facial intégral AGA et des bouteilles de plongée d’un appareilrespiratoire à air comprimé (ARAC) lors de chaque exercice. La charge selon l’équipement deplongée a été quantifiée au moyen de balayages volumétriques et en mesurant le champ visuelet l’amplitude de mouvement cervical. L’évaluation sous l’eau comportait des exercices demouvement d’amplitude de tout le corps.

L’exécution des tâches consistait en une simulation d’exercices de lutte contre les mineset comportait des activités de motricité fine (nouage de cordes et assemblage par boulonset écrous), de motricité globale (transfert du poids) et de recherche visuelle. Toutes lestâches sous l’eau ont été enregistrées au moyen de caméras étanches GoProTM et évaluéesen fonction du délai pour les mener à bien, de l’indice de charge de travail (ICT) de laNASA et d’un questionnaire subjectif. Malgré le nombre peu élevé de participants, lesrésultats ont montré des tendances qui correspondaient à l’efficacité des tâches sur lesquellesla charge exerce une influence défavorable, comme l’indique une amplitude de mouvementréduite. L’exception étant l’assemblage par boulons et écrous, celui-ci a semblé profiter d’uneplus grande stabilité qu’apportait une combinaison plus contraignante. L’étude confirmel’importance d’établir des mesures objectives pour évaluer la charge pouvant avoir uneincidence sur l’efficacité du travail des plongeurs. On a souligné la difficulté de déterminerla charge globale de l’équipement de plongée dans un environnement sous-marin, ainsi queles lacunes sur le plan de la recherche, des outils, des ressources et des installations pourappuyer des recherches approfondies sur les facteurs humains relatifs à la plongée.

Importance pour la défense et la sécurité

Le présent rapport contient les résultats d’une étude pilote dans laquelle on utilise del’équipement, des méthodes et des outils ergonomiques novateurs afin de mesurer l’efficacitédes plongeurs qui procèdent à une simulation des tâches relatives à la lutte contre les mines.Les résultats de cette étude permettront de fournir des renseignements sur les facteurs hu-mains futurs et la recherche en ergonomie physique pour appuyer la description, la concep-

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tion, la mise au point et l’évaluation des vêtements, de l’équipement et des plateformes deplongée. On énonce des recommandations supplémentaires dans le but de déterminer leslacunes en matière de recherche, d’outils, de ressources et d’installations pour appuyer desrecherches approfondies sur les facteurs humains relatifs à la plongée.

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Table of contents

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

Significance for defence and security . . . . . . . . . . . . . . . . . . . . . . . . . . . i

Résumé . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

Importance pour la défense et la sécurité . . . . . . . . . . . . . . . . . . . . . . . . ii

Table of contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

List of figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

List of tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Purpose of the study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2.1 Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2.2 Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.3 Suit conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.4 Participant Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.4.1 Anthropometry (body size) . . . . . . . . . . . . . . . . . . . . . . 6

2.4.2 3D scanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.4.3 Scan Postures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.4.4 Range of motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.4.4.1 Warm up . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.4.4.2 Cervical Range of Motion . . . . . . . . . . . . . . . . . 9

2.4.5 Baseline field of view . . . . . . . . . . . . . . . . . . . . . . . . . . 10

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2.4.6 In-water performance-based tasks . . . . . . . . . . . . . . . . . . . 11

2.4.6.1 Range of Motion . . . . . . . . . . . . . . . . . . . . . . 12

2.4.6.2 Fine motor task – Two-tiered horizontal bolt board . . . 15

2.4.6.3 Fine motor task – Rope Tying . . . . . . . . . . . . . . . 15

2.4.6.4 Gross motor task – Weight Transfer . . . . . . . . . . . . 16

2.4.6.5 In-Water Field visual search task . . . . . . . . . . . . . 17

2.4.6.6 Subjective questionnaires . . . . . . . . . . . . . . . . . . 18

3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3.1 Data analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3.2 Characterization of participants . . . . . . . . . . . . . . . . . . . . . . . . 19

3.3 3D Scanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.4 Field of view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.5 Range of motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.6 Task performances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3.7 Range of motion vs. Task performances . . . . . . . . . . . . . . . . . . . . 25

3.8 Subjective feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4.1 CROM vs. Visual search . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4.2 Fine motor tasks vs whole body ROM . . . . . . . . . . . . . . . . . . . . 31

4.3 Range of motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.4 Suit differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.5 Operations and task analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.6 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

4.7 Quantification of system encumbrance and mobility . . . . . . . . . . . . . 35

4.7.1 Bulk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

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4.7.2 Ensemble Stiffness . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

4.7.3 Ensemble weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

4.7.4 Motion capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.7.5 Biomechanical modeling . . . . . . . . . . . . . . . . . . . . . . . . 38

5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Annex A: Participant information sheet . . . . . . . . . . . . . . . . . . . . . . . . . 44

Annex B: NASA TLX and Encumbrance rating questionnaires . . . . . . . . . . . . 47

Annex C: Summary of DCIM/DRDC – Sponsored reports on the Human Factors ofMine Counter Measures Operations . . . . . . . . . . . . . . . . . . . . . 50

List of symbols/abbreviations/acronyms/initialisms . . . . . . . . . . . . . . . . . . 53

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List of figures

Figure 1: EDUG static dive tank. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Figure 2: Suit conditions- Kodiak (left) , Fusion (middle), wetsuit (right).Retrieved from https://www.whitesdiving.com/military/.Reprinted with permission from Harald Knippelberg, 11 September 2017. 4

Figure 3: Five-finger neoprene gloves back (left), left (right). . . . . . . . . . . . . 4

Figure 4: AGA dive mask. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 5: CABA dive tanks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 6: Landmark locations for semi-nude 3D scans. . . . . . . . . . . . . . . . . 6

Figure 7: 3D scanner roundels used for landmark identification. . . . . . . . . . . 7

Figure 8: VITUS XXL laser scanning system. . . . . . . . . . . . . . . . . . . . . . 7

Figure 9: 3D standing scan postures. . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 10: Cervical range of motion with the Qualisys optical motion capture system. 10

Figure 11: Field of view measuring tool (Perimeter). The green LED is visible inthe foreground arc of the perimeter. . . . . . . . . . . . . . . . . . . . . 11

Figure 12: Anthropometric range of motion measures. Top row: shoulderabduction, hip flexion, trunk flexion. Bottom row: left trunk rotation,right trunk rotation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 13: Waterproof wide lens GoPro camera in-water placement. Front view(left,) overhead view (right). . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 14: Location of high colour-contrast marker placement. . . . . . . . . . . . . 14

Figure 15: The two tiered horizontal bolt board. . . . . . . . . . . . . . . . . . . . 15

Figure 16: Bowline with two half-hitch knot used for Rope Tying task. . . . . . . . 16

Figure 17: Gross motor weight transfer task. . . . . . . . . . . . . . . . . . . . . . . 17

Figure 18: Visual search task. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 19: Mean and Standard Deviation (SD) of weight of 5 participants undervarious levels of encumbrance. . . . . . . . . . . . . . . . . . . . . . . . . 20

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https://www.whitesdiving.com/military/

Figure 20: Three dimensional scans of the: a) Semi-nude, b) Wetsuit, c) Fusion,and d) Kodiak dive suits with AGA mask and CABA tanks. . . . . . . 20

Figure 21: Field of view map for each participants left and right eye, with andwithout (baseline) the AGA mask. . . . . . . . . . . . . . . . . . . . . . 21

Figure 22: Mean values for all participants field of view in the left and right eye,with and without the AGA mask. . . . . . . . . . . . . . . . . . . . . . . 22

Figure 23: Comparison of mean cervical range of motion movements in variouslevels of encumbrance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 24: Comparison of mean cervical range of motion as compared to semi-nudereference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 25: Comparison of trunk and limb mean range of motion, in various levels ofencumbrance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 26: Task performance scores for A) Nuts and Bolts, B) Weight Transfer, C)Rope Tying, and D) Visual Search in the Wetsuit, Fusion, and Kodiaksuit conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 27: Mean cervical range of motion in a) extension, b) left rotation, and c)right lateral flexion, against visual search task times in the Wetsuit,Fusion, and Kodiak suit condition. . . . . . . . . . . . . . . . . . . . . . 26

Figure 28: Mean a) horizontal shoulder flexion and b) cervical flexion against theNuts/Bolts scores in the Wetsuit, Fusion, and Kodiak. . . . . . . . . . . 26

Figure 29: Participants’ rope tying times plotted against range of motion (ROM)for horizontal shoulder flexion in all conditions. . . . . . . . . . . . . . . 27

Figure 30: W= Wetsuit, K= Kodiak, F= Fusion. Custom Likert scaled divingquestionnaire with the order of mean responses upon wearing theWetsuit, Kodiak, and Fusion. . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 31: W= Wetsuit, K= Kodiak, F= Fusion. Task Load Index questionnairewith the order of mean responses upon wearing the Wetsuit, Kodiak,and Fusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 32: Memorial University’s flume facility demonstrating use in divingoperations research. Copyright by the Fisheries and Marine Institute ofMemorial University of Newfoundland. Reprinted with permission fromPaul Winger, 12 September 2017. . . . . . . . . . . . . . . . . . . . . . . 34

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Figure 33: Example of the Qualisys system adapted for underwater motioncapture. Retrieved from https://www.flickr.com/photos/qualisys/.Reprinted with permission from Scott Coleman, Qualysis, NA, 11September, 2017. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Figure 34: Biomechanical analysis of the front crawl as represented by theSWUMsuit model using Anybody Modeling SystemTM. Retrieved fromhttp://www.swum.org/anybody_crawl.avi. Adapted with permissionfrom the author, Motomu Nakashima, 15 September 2017. . . . . . . . 39

Figure B.1: NASA Task Load Index (TLX). . . . . . . . . . . . . . . . . . . . . . . 47

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https://www.flickr.com/photos/qualisys/

http://www.swum.org/anybody_crawl.avi

List of tables

Table 1: Participant demographic and anthropometric summary statistics (Mean± SD). CC= Chest circumference, WC= Waist circumference C7=Height of the 7th cervical vertebrae. . . . . . . . . . . . . . . . . . . . . 19

Table B.1: Subjective rating questionnaire on the effect of encumbrance on taskperformance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

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Acknowledgements

The authors of the report wish to acknowledge the support and expertise of the membersof the Canadian Forces Environmental Medicine Establishment Experimental Diving andUndersea Group (EDUG). In particular Lt (N) Greg Richardson who, as a subject mat-ter expert, provided valuable advice and insight into mine counter measures operations.His assistance in coordinating personnel and access to EDUG facilities was essential to thesuccess of this trial. CPO2 Paul Walsh acted as the Chief Diver during experimental ac-tivities, ensuring effective communication between DRDC, EDUG and study participantsand ensuring that a safe environment was maintained at all times. Finally, the authors aregrateful to the divers from the HMCS York – Reserve Dive Team who graciously volunteeredto participate as experimental subjects in this study.

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1 Introduction1.1 Background

Diving is an imperative role in the Royal Canadian Navy (RCN) and is comprised of special-ized tasks and missions. Such missions include Mine Counter Measures (MCM), ExplosiveOrdnance Disposal (EOD), Battle Damage Repair (BDR), Force Protection Support (FPSupport) and Under Water Engineering. There are currently a lack of objective tools andmethods to inform the procurement of dive ensembles the Canadian Armed Force (CAF)diving community. To support the requirement for the development of an objective frame-work to guide the development and validation of requirements of CAF diving equipment,a Human Factors Program Plan (HFPP) for the CAF diving program has been developed(Angel and Tack, 2015). Along with the development of the complementary Human FactorsTest Plan (Angel and Tack, 2015), DRDC and the Experimental Diving Undersea Grouphave sound guidance on the implementation of Human Factors principles in all aspects ofsystem design and acquisition.

Working in an immersed environment imposes a number of inhibiting factors that canhave an impact on task performance. Environmental factors may include: depth, visibility,buoyancy, turbulence, drag force, and water temperatures (Baddeley, 1966; Bachrach &Egstrom,1974; Hancock & Miller, 1986; Arieli et. al, 1997; Zander & Morisson, 2008; Hoff-mann & Chan, 2012). Since these circumstances may often be beyond the diver’s control,certain precautionary measures must be accounted for to warrant the safety and success ofthe mission. Despite adequate skill levels and physical conditioning needed for the safetyand success of a mission, the dive garments and equipment may provide an impedimentto this objective. Material characteristics such as the weight, thickness, stiffness, buoyancyand friction can contribute to a decrease in performance (Adams & Keyserling, 1995; Huck,1988; Uglene et. al, 1998). Of those factors, the bulk and configuration of the ensemblesimpose encumbrance to the diver and can lead to a greater decrease in task performance(Huck, 1988; Uglene et. al, 1998; Son et. al, 2010).

While personal protective equipment (PPE) is meant to protect the worker from their workenvironment (Adams, et al., 1994) a decrement in task performance may be attributedto the PPE’s effect on the worker’s range of motion (ROM). Range of motion is definedas the maximum angular change at a joint, measured in degrees from a reference point(Chaffin et. al, 1984). A reduced ROM appears to be a consequence of wearing PPE (Adamsand Keyserling, 1993; Adams, et al., 1994; Adams & Keyserling, 1995; Coca et. al, 2010;Margerum et. al, 2012). This is exemplified by a 1987 survey of Canadian military andcommercial helicopter pilots. It revealed that 72% of the military and 86% of the commercialpilots found their survival suit to restrict movement (Gaul & Mekjavic, 1987).

Mobility, dexterity, and comfort are inherently traded off for protection (Bachrach, Egstrom& Blackmun, 1975; Banks 1979; Zander & Morisson, 2008). By excessively compromisingperformance, the divers safety could be at risk; that is, if an emergency arises, a cumbersomeensemble could impede the divers ability to escape the hazardous environment since ROM,

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movement speed, and accuracy are reduced, and exertion is increased (Adams, Slocum, &Keyserling,1994; Adams & Keyserling, 1995).

Field of view (FOV) also plays a role in task performance limitations, since dive maskscan obstruct peripheral vision. A restricted FOV can decrease the velocity and accuracyof movement and affect overall task performance (González-Alvarez et. al, 2007; Toet et.al, 2007). Large head and whole body movements are required to compensate and orientindividuals with a limited FOV (Alfano & Michel, 1990). Although, these compensatorymovements may be difficult to carry out while wearing a restricting ensemble, a less im-peding garment could save on labour and physiological costs as productivity would increase(Adams et al., 1994). Unfortunately, the quantitative relationship between ensemble en-cumbrance and task performance is poorly understood. By quantifying and parameterizingencumbrance and its functional restrictions, manufacturers would be able to develop PPEthat could better accommodate the safety and efficiency of the worker (Adams & Keyserling,1993).

1.2 Purpose of the study

The purpose of this pilot study is to evaluate and apply ergonomics-based tools andmethodologies available through the Comprehensive Ergonomics-based Tools and Tech-niques (CETTs) capability to aid in the development of a standardized methodology toevaluate dive ensembles and equipment by assessing diver performance in above and under-water tasks. Relevant CETTs capabilities include 3D whole-body laser scanning, and opticaland video-based motion analysis. It is hypothesized that ensemble encumbrance, depictedfrom ROM and 3D scanning measurements, will be positively correlated with decreasedmobility and fine and gross motor task performance.

2 Methods2.1 Participants

Royal Canadian Navy Reserve Divers from the HMCS York Naval Unit were recruited toparticipate in this pilot study. Participants were informed that this study had receivedDRDC Human Research Ethics Committee approval and were briefed on its purpose, risksand benefits of this study. They were provided with a copy of the Participants Informationsheet (Annex A) to provide them with an overview of the study. The inclusion criteria wereas follows: qualified Canadian Armed Forces (CAF) divers, hold current qualifications andwere deemed proficient and medically fit to dive, male or female, between the ages of 18–60years. All participants were briefed as to the purpose, risks and benefits of the study by thePrincipal Investigator and signed the Informed Consent form. Volunteers were informed oftheir right to withdraw from the trial at any time.

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2.2 Location

All experimental trials were conducted at DRDC Toronto Research Centre. Dry land ac-tivities were held in the CETTs laboratory, while in-water diving activities were held inthe Experimental Diving and Undersea Group (EDUG) static tank (Figure 1). The EDUGstatic tank is a water filled 8’ x 8’ x 10’ facility maintained at a temperature of approxi-mately 21◦C. A viewing window built into one of the tanks walls allowed for viewing of allunderwater activities. An underwater speaker system allowed for instruction to be commu-nicated to the divers from the experimenters and dive master above.

Figure 1: EDUG static dive tank.

2.3 Suit conditions

Three diving suits were evaluated as part of the this study. Two dry suits, Kodiak (360 Dry-suit, Whites Manufacturing, BC) and Fusion (Tactical MCM Drysuit, Whites Manufactur-ing, BC) were designated as the encumbered conditions (Figure 2). The Kodiak dry suitis made up of supplex multi-laminate fabric. It can be measured and custom fitted to anindividual. The Fusion dry suit is made up of Supplex R⃝ multi-laminate Denier bi-laminatedfabric and is available in 5 different stock sizes to fit a range of sizes. A thin undergarment


was worn underneath each of these garments to improve comfort and thermal protection.A standard wet suit (Brooks Dive Gear, BC) (Figure 2) served as the reference conditionas it was deemed to be the least bulky suit. The wetsuit is comprised of 6mm polyethylenethroughout the suit, with the exception of 4mm at the back of the knees. Each diver per-formed a sequence of above and underwater tasks in each of the three suit conditions. Theorder of suits worn by each diver was randomized and counterbalanced to minimize poten-tial effects due to learning or fatigue. Each diver also wore 3 mm thick, 5-finger neoprenegloves that had titanium-slick-skin lined palms (Whites, BC) (Figure 3). An AGA mask(Aqua Lung, CA) (Figure 4) and Compressed Air Breathing Apparatus (CABA) (Figure 5)was used during the in-water tasks.

Figure 2: Suit conditions- Kodiak (left) , Fusion (middle), wetsuit (right). Retrieved fromhttps://www.whitesdiving.com/military/ . Reprinted with permission from Harald

Knippelberg, 11 September 2017.

Figure 3: Five-finger neoprene gloves back (left), left (right).


https://www.whitesdiving.com/military/

Figure 4: AGA dive mask.

Figure 5: CABA dive tanks.


2.4 Participant Characteristics2.4.1 Anthropometry (body size)

A total of four measures were manually collected for each participant using anthropometricinstruments such as calipers and a measuring tape. The measures were obtained for thepurposes of characterizing each participant.

Measures taken include:

1. Stature;

2. Weight;

3. Chest circumference; and

4. Waist circumference.

2.4.2 3D scanning

Participants underwent a 3D scanning process, similar to that described by Jones et. al.,(2013). This methodology describes scanning participants in semi-nude and encumberedconditions and in multiple postures. For this study, 3D scans were obtained in each of theFusion, Kodiak, and wetsuit conditions. In order to provide additional utility for futureanalysis, and additional identification and marking of 26 anatomical landmarks (Figure 6)was included in this study.

Figure 6: Landmark locations for semi-nude 3D scans.

Following the method developed in the 2012 Canadian Forces Anthropometric Survey (Keefeet al., 2015), participants were provided with a private change area where they undressed


to the level of their underwear and don compression (unpadded bicycle) shorts and a sportsbra (for women). Land marking was done in a private area where a measurement teammember then marked anatomical reference points on their body by drawing a small cross“+” with a hypoallergenic eyeliner pencil. The measurement team member identified thelandmarks by sight, palpation and movement. The measurement team included membersof each sex, and on request, measurements were taken by an observer of the same sex. Toenhance the contrast of the landmark for post scan identification, a self-adhesive, 12 mmhigh contrast roundels was placed each landmark (Figure 7).

Figure 7: 3D scanner roundels used for landmark identification.

Three-dimensional body scans were obtained in a standing posture using the the VITUSXXL laser scanning system (Human Solutions of North America, Cary, NC) (Figure 8). Thissystem includes 4 laser scanning columns bolted into an aluminum frame, a personal com-puter with a monitor, and an analog to a digital signal converter box. A laser sensor movedlinearly along the participant, from top to bottom, to record the scan image. Immediatelyafter scanning, a visual check of the scan for completeness, moving artefacts, or incorrectposture was completed. Anthroscan v3.05 software (Human Solutions of North America,Cary, NC) was used to process the 3D images, stitch the multiple images together, correctscan anomalies and extract dimensions captured by the VITUS XXL whole body scanner.

Figure 8: VITUS XXL laser scanning system.


2.4.3 Scan Postures

Four standing scan postures (Figure 9) were taken for each participant in the semi-nude aswell as each of the three suit conditions. Four postures were required to gather sufficientdata to account for occlusions or voids in the scan and to account for shifts in the clothingensemble with posture. Each scan took approximately 12 seconds to complete. To supportthe load of the CABA tanks and ensure a consistent and still scan posture, an supportingstand was fabricated and adjusted for the height of each participant.

Figure 9: 3D standing scan postures.


2.4.4 Range of motion2.4.4.1 Warm up

Prior to each ROM assessment, participants were instructed to perform a standardizedwarm-up stretching routine as described by Gerhardt et al., (2002) to enhance performanceand reduce their risk of injury. This warm-up included a brief period of a sub-maximalaerobic warm-up activity and a bout of static stretching. The researcher-led dynamic warm-up included the following components:

• Bent Over Rotations: Begin with feet at a comfortable stance wider than shoulderwidth. Bend over at hips with arms fully extended at sides at 90 degrees from torso.Begin by swinging right arm towards left foot and repeating on opposite side. Continuethis motion through comfortable range, but do not strain. Continue this motion for30 seconds.

• Arm Circles: Stand with feet shoulder width apart and knees slightly bent. Raisearms to a 90 degree angle from the torso with arms fully extended. Begin by makingsmall circles by bringing arms forward and gradually increase to a full range of shouldermotion. Change direction at 15 seconds. Repeat motion with arms moving in oppositedirection for 15 seconds.

• High Knee Hold: Walking while raising knees to chest: once knee has reachedhighest point of ROM, pull knee till a slight stretch is felt, continue with movement.Continue motion for 30 seconds alternating legs during walking.

• Lunge walk and trunk rotation: Begin by taking a large step in a forward directionand lowering body until the forward knee is at 90 degrees. While at lowest positionrotate upper body towards forward leg through full ROM until slight stretch is felt.Bring other leg forward and repeat on other side. Continue lunge walk for 30 seconds.

• Leg swings (forward/backward): Stand with side to the wall. Extend arm side-ways for support and move one arm length away from the wall. With hand on thewall, raise the leg closest to wall off of ground and begin by swinging it fore and aft,through the full ROM without straining. Continue for 15 seconds on one leg. Rotateposition and repeat on opposite leg for an additional 15 seconds.

2.4.4.2 Cervical Range of Motion

Cervical range of motion (CROM) was the only functional task evaluated on dry-land.The primary reason was that a pilot study revealed that, during in-water testing, markersplaced on the head could not be tracked reliably in all planes of motion due to their closeplacement and resolution of the video recording. While it was preferred to conduct thisevaluation in-water, it was decided to use a more precise, laboratory-based, optical trackingsystem. Conducting the CROM measures on dry-land also made it easier to isolate theneck movement from the compensating torso movements that naturally occurred duringin-water test. As the hoods worn in each dive condition were form fitting, it was anticipated


that the hydrostatic pressure experienced would have minimal impact on suit compression,unlike the body suits which were loose fitting in the Fusion and Kodiak conditions. Finally,dry-land evaluation of CROM allowed for an unencumbered test condition. This could notbe done for the encumbered condition due to the temperature of the static tank was toocool for semi-nude immersion.

Three motion capture markers were placed on a headpiece to record cervical motions inthe x, y, and z-axis with the use of the Qualisys optical motion capture system (QualisysNorth America, Highland Park, Ill) (Figure 10). Range of motion data were collected forneck flexion/extension, lateral bending and axial rotation. Each exercise conducted in thesemi-nude and all suit conditions. Suit conditions included the CABA tanks and AGA mask.Each motion was repeated twice and movements were captured at 60 frames per second,graphed, and recorded to the nearest degree.

Figure 10: Cervical range of motion with the Qualisys optical motion capture system.

2.4.5 Baseline field of view

A baseline, functional field of view measure of both the baseline (no mask) and maskconditions were recorded with the use of a perimeter device (Figure 11). An eye patch wasworn by each participant so that the monocular visual field of view could be assessed foreach eye. Participants were instructed to place their chin on the chinrest such that theireye was placed at the reference pole of a semi-circular perimeter device. The perimeter wasmarked with angular coordinates, and a green light-emitting diode (LED) was installed on


a slider attached that could be placed at random coordinates along the bar. Once placed inposition, the LED was illuminated by the investigator by pressing a remote button. Withtheir head in a fixed position, the participant proceeded to visually scan the perimeter.Successful visual identification of the LED was recorded if the participant could see thepoint light emanating from the LED, rather than its glare. The placement of the LED wasrandomly adjusted to titrate the limits of the field of view . The limits to the field of viewwere recorded in degrees and the perimeter bar was re-adjusted at 0, 45 and 180 degreesto obtain measures for the left/right horizontal, diagonal, and up/down vertical arcs. Blackscreens surrounded the area to remove any background visual distractions to facilitate theidentification of the LED target.

Figure 11: Field of view measuring tool (Perimeter). The green LED is visible in theforeground arc of the perimeter.

2.4.6 In-water performance-based tasks

During all in-water tasks, the divers were fully equipped wearing fins, a CABA air tank,AGA mask, 5-finger neoprene gloves, and weighted belts for each suit condition. Note thatthis differs from the in-water ROM test where ankle weights were worn instead of fins tomaintain stability under water. All tasks were completed in approximately 1hr, for eachexperimental condition.

As water temperature could not be regulated above a room temperature of 20◦C, a semi-nude condition could not be used to serve as a reference condition due to concerns of muscleand body cooling. As an alternate, the wetsuit condition was considered as the control as itwas considered to be the less bulky of the three suit conditions. Unlike the CROM measures,


an dry-land whole body ROM was not conducted as a buoyant environment was requiredto support the weight of the CABA tanks worn by the divers. Second, it was anticipatedthat buoyancy and hydrostatic forces would act on the suit, affecting performance. Thus, itwas assumed that dry-land ROM would not be indicative of in-water ROM for these tasks.

All tasks were demonstrated to the participants on dry land, and they were provided anopportunity to practice the fine motor and Rope Tying tasks until it was determined bythe participant and experimenter that they were familiar and proficient with the tasks.

2.4.6.1 Range of Motion

As buoyancy jeopardized postural stability, for this task only, the divers were equipped withankle weights instead of swimming fins to assist with their stability

A set of 7 range of motion movements (Figure 12), adapted from Bachrach, Egstrom &Blackmun, (1975) were used as these movements have been previously justified by theseauthors for diving application. All ROM movements were encouraged to be completed tothe participant’s fullest extent. Each motion was performed twice to provide an averagerange of motion value.

Figure 12: Anthropometric range of motion measures. Top row: shoulder abduction, hipflexion, trunk flexion. Bottom row: left trunk rotation, right trunk rotation.


These movements were recorded underwater with the use of two waterproof, wide anglelens GoPro camera (GoPro, San Mateo, CA) placed above and to the front of the diver(Figure 13).

Figure 13: Waterproof wide lens GoPro camera in-water placement. Front view (left,)overhead view (right).

High colour-contrast (SOLAS orange) markers were affixed to the divers’ torso, as well asupper and lower extremities to facilitate the identification and tracking of these landmarks(Figure 14). The 2D footage was used for kinematic analysis, specifically measuring changesof joint angles throughout the range of motions with the use of the video analysis softwareKinovea v0.8.15 (Kinovea, France).

All ROM movements were demonstrated and practiced in an unencumbered (shorts, t-shirt)condition before entering the dive tank. The diver then donned their diving gear and enteredthe dive tank, where these movements were repeated. An underwater speaker/microphonesystem was used to communicate with the diver to guide them through the movements.


Figure 14: Location of high colour-contrast marker placement.


2.4.6.2 Fine motor task – Two-tiered horizontal bolt board

Participants entered the 8’ x 8’ X 10’ static dive tank and positioned themselves at a centrallocation on the tank floor. A custom stainless steel version of a two-tiered horizontal Nutsand Bolts task board was fixed to a wall located approximately 1m above the floor (Fig-ure 15). The bolt board has 8 colour-coded bolts on the upper tier, arranged in descendingdiameter from left to right. Each of these bolts held two sets of nuts and washers arrangedin alternating order. Each bolt size/colour combination on the upper tier was representedby two corresponding bolts on the lower tier. The objective of this task was to transfer anut and washer pair from the upper tier to a corresponding, unused bolt on the lower tier.This done in an ordered manner, beginning with largest diameter bolt in the upper left tierand working rightward to the smallest diameter bolt. The nuts were required to be fullytightened allowing no movement of the washers. Task performance was scored as the totalnumber of nut/washer pairs transferred within a 5 minute period. Removal of the gloveswas not permitted, although, use of a working knife was permitted, if needed.

Figure 15: The two tiered horizontal bolt board.

2.4.6.3 Fine motor task – Rope Tying

The second fine motor task consisted of tying a bowline knot (Figure 16) followed by two halfhitches around an anchor. They were required to immediately un-tie the knot afterwards.This was repeated for a total of three times. This task was timed, and the divers wereencouraged to perform this task as quickly as they could.


Figure 16: Bowline with two half-hitch knot used for Rope Tying task.

2.4.6.4 Gross motor task – Weight Transfer

The gross motor task was designed to simulate the transfer of debris or tools on a mission.Milk crates were secured in opposing corners of the static tank and a 4.5kg weight wastransferred from one milk crate to the other as many times as possible within 5 minutes(Figure 17). Transfer techniques varied, but the diver was instructed to place the weight onthe bottom of the milk crate. Throwing or dropping of the weights into the basket was notpermitted.


Figure 17: Gross motor weight transfer task.

2.4.6.5 In-Water Field visual search task

Three grid boards of approximately 1m x 1.5m with a 6 x 5 grid of randomized numberswere fixed on the walls of the static tank (Figure 18). The experimenter would present theparticipant with a number through the observation window prompting the diver to scan andlocate the shown number. Once the number was located, the diver was required to touch theidentified number for confirmation. A total of 10 numbers were presented and the averagetime from presentation to identification was recorded. There were 3 configurations of gridboards, all of which were presented in a counterbalanced manner across participants tocontrol for any learning effects. Grid boards were fixed to the walls at two different heightsin order to increase the level of difficulty of this task.


Figure 18: Visual search task.

2.4.6.6 Subjective questionnaires

At the end of each suit condition trial, a Task Load Index (TLX) questionnaire (Hart& Staveland, 1988) (Annex B, Figure B.1) as well as a custom Likert Scale questionnaire(Annex B, Table B.1) were distributed to obtain subjective measures. These subjective mul-tidimensional assessments complemented the objective measures and provided additionalinsight into the effect of encumbrance on underwater task performance.

3 Results3.1 Data analysis

A total of five participates, four males and one female, participated in this study. Dueto limited number of participants, the statistical power of this study was deemed too lowto warrant performing inferential statistical analysis. However, descriptive analysis wasperformed to identify performance trends.

Encumbrance is defined as the bulk, weight and stiffness of clothing and equipment. As thequantification of these factors require special considerations in the underwater environment(see Section 4.7) the analysis of 3D scans was not performed at this time . For the purposes ofthis analysis, encumbrance was defined as the restriction to divers’ mobility The relationship


between range of motion, the independent variable (IV), and task performance scores, thedependent variable (DV), were organized and presented with descriptive statistics such asmean and standard deviation. Cervical range of motion, whole body range of motion, andtask performance scores were presented in histograms to summarize the data. Scatter plotswith a line of best fit between each suit condition’s DV and IV were utilized to analyzespecific trends.

Subjective ratings of encumbrance and task load are reported without statistical inference,but trends and scores are discussed with reference to clothing condition and task perfor-mance.

3.2 Characterization of participants

Table 1 provides a summary of the demographic and anthropometric characteristics of theparticipants.

Table 1: Participant demographic and anthropometric summary statistics (Mean ± SD).CC= Chest circumference, WC= Waist circumference C7= Height of the 7th

cervical vertebrae.

CAF Diving Age Weight Stature CC WC C7Experience (years) (kg) (cm) (cm) (cm) (cm)

(years)6.8±5.6 35.0±7.2 82.6±10 175.0±8.8 103.0±9.2 88.4±7.6 149.4±7.8

Comparison of the weights of the dive suits revealed minor differences in dry weight, withthe wetsuit being the lightest at 5.2±0.5 kg and the Fusion and Kodiak suits weighing5.9±0.6 and 6.2±0.4 kg respectively. Addition of the CABA tanks added an average of43.8 kg of supplementary weight to the participants (Figure 19).


Figure 19: Mean and Standard Deviation (SD) of weight of 5 participants under variouslevels of encumbrance.

3.3 3D Scanning

To date, the three dimensional scans have not been analysed, as DRDC is currently workingwith academic and international partners to devise a standardized methodology to quantifybulk metrics from 3D scans of clothing and equipment. Figure 20 provides an example ofthese 3D scans in the various levels of encumbrance measured.

Figure 20: Three dimensional scans of the: a) Semi-nude, b) Wetsuit, c) Fusion, and d)Kodiak dive suits with AGA mask and CABA tanks.


3.4 Field of view

Figure 21, provides an overview of all participants’ field in the AGA mask and baseline (nomask) condition. It is evident that, there is a large degree of inter-participant variabilitythat appears to be greater in the left eye.

Figure 21: Field of view map for each participants left and right eye, with and without(baseline) the AGA mask.

By plotting the means of these values it is apparent that, when compared to the baselinecondition, there is a bilateral restricted field of view with AGA mask affecting lateral anddownward vision (Figure 22).


Figure 22: Mean values for all participants field of view in the left and right eye, withand without the AGA mask.

3.5 Range of motion

Figure 23 provides a comparison of cervical range of motion (CROM) across the four exper-imental conditions. Differences in CROM were observed between the levels of encumbrancewith the semi-nude and Wetsuit condition appearing to allow the greatest CROM in allmovements, with the exception of the Fusion, which performed slightly better than theWetsuit in the lateral left flexion task. In general, the Fusion and Kodiak suits performedsimilarly across all range of motion movements, with the Fusion displaying better perfor-mance in right rotation, flexion and lateral left flexion and the Kodiak allowing greater neckextension. Right rotation showed the greatest difference between each of the suit conditionswith a consistent decrease in CROM.

When compared against the seminude condition, all encumbered conditions provided somedegree of restriction to range of motion, with the Fusion and Kodiak tending to restrictmotion more than the wetsuit in all CROM motions with the exception of lateral leftflexion Figure 24. Right cervical rotation is restricted the most of all motion, likely due tothe collision between the mask regulator and beacon mounted on the diver’s right shoulderstrap.


Figure 23: Comparison of mean cervical range of motion movements in various levels ofencumbrance.

Figure 24: Comparison of mean cervical range of motion as compared to semi-nudereference.


Figure 25 provides a comparison of whole-body ROM across the three suit conditions.Recall that due to the cool (20◦C) water temperature, in-water tasks were not completedin the semi-nude condition. For all in-water tasks, the wetsuit was considered to be thereference condition. Differences between suit conditions were subtle across all movementswith the possible exception of shoulder flexion and abduction where it appears that thewetsuit afforded slightly more shoulder mobility. Due to the low number of participants inthis study, these results indicate trends across suit conditions and should not be assumedto be conclusive.

Figure 25: Comparison of trunk and limb mean range of motion, in various levels ofencumbrance.

3.6 Task performances

Figure 26 indicates that performance in the Wetsuit condition was poorest in the fine motordexterity tasks (i.e., Nuts and Bolts, Rope Tying). In contrast, the Fusion suit condition wasassociated with the poorest performance in the gross motor, (i.e., mobility related WeightTransfer and Visual Search tasks). Comparing the Fusion and Kodiak suits, fine motorperformance was similar between the two suits however, the Kodiak was associated withmarkedly better performance in the weight transfer and visual search tasks.


Figure 26: Task performance scores for A) Nuts and Bolts, B) Weight Transfer, C) RopeTying, and D) Visual Search in the Wetsuit, Fusion, and Kodiak suit conditions.

3.7 Range of motion vs. Task performances

Figure 27 provides exemplars of the relationship between CROM and Visual Search Taskperformance in the three suit conditions. In each example, the Fusion was associated withthe slowest completion of the visual search task, whilst having the most restriction to CROMin extension, left rotation, and right lateral flexion motions. Despite allowing the greatestCROM, the performance in the wetsuit was slightly poorer than in the Kodiak suit.


Figure 27: Mean cervical range of motion in a) extension, b) left rotation, and c) rightlateral flexion, against visual search task times in the Wetsuit, Fusion, and Kodiak suit

condition.

A reverse trend was noted in the Nuts and Bolts task (Figure 28) where the suit mostrestrictive to horizontal shoulder ROM and CROM flexion (Kodiak) was associated withbest performance in the Nuts and Bolts task. While this may seem counterintuitive, itsuggests that certain tasks may benefit from restricted range of motion by providing astabilizing function during fine motor tasks.

Figure 28: Mean a) horizontal shoulder flexion and b) cervical flexion against theNuts/Bolts scores in the Wetsuit, Fusion, and Kodiak.


Increased range of motion of the upper body, was associated with a trend towards improvedperformance in the Rope Typing Task (Figure 29). Observation of these data suggest a curvi-linear relationship such that improvement in task is not apparent until shoulder range ofmotion exceeds an approximate 90 degrees, however, due to the low number of participants,the significance or validity of this observation cannot be determined.

Figure 29: Participants’ rope tying times plotted against range of motion (ROM) forhorizontal shoulder flexion in all conditions.

3.8 Subjective feedback

Figure 30 provides a summary of responses to the custom, 5-point Likert diving ques-tionnaire. In general, the majority of responses tended to reside in the ‘undecided’ columnindicating that the participants felt neither adversely encumbered or aided by the suit worn.Participants wearing the Wetsuit and Kodiak tended to indicate that they did not feel thatthe level of restriction and bulk adversely affected functional task performance. Question10 elicited the greatest discrepancy between the suit conditions with participants indicatingthat they agreed that the bulk and restrictiveness of the Kodiak and Wetsuit did not affecttheir task performance. In comparison, the participants wearing the Fusion suit tended tofeel that their performance was adversely affected by this suit, as indicated by disagreeingwith this statement.

Figure 31 Provides the responses to the NASA Task Load Index (TLX), indicating that, onaverage, participants found the performance tasks to be low to moderately demanding. In allbut the one question, task performance in the Fusion was ranked as the most demanding ofthe three suit conditions. Wetsuit and Kodiak conditions scored similarly with the exceptionof task Performance and task Frustration which was scored as being less demanding in theKodiak suit.


Figure 30: W= Wetsuit, K= Kodiak, F= Fusion. Custom Likert scaled divingquestionnaire with the order of mean responses upon wearing the Wetsuit, Kodiak, and

Fusion.


Figure 31: W= Wetsuit, K= Kodiak, F= Fusion. Task Load Index questionnaire withthe order of mean responses upon wearing the Wetsuit, Kodiak, and Fusion.


4 Discussion

Due to the small number of participants in this pilot study (5), inferential statistics werenot possible. As a result, the data presented in this report are not necessarily generalizableto a broader, diver population. Despite the limited scope and statistical power of thisstudy, it was apparent that there were trends in task performance and subjective ratingsassociated with wearing different dive ensembles. This is important as it suggests that taskperformance may be explained by differences in the configuration, fit and restriction ofmovement afforded by different diving ensembles. The following discussion focuses on therelationship between dive ensemble encumbrance and task performance. This is followed byan assessment of key challenges and opportunities to inform the development of ergonomics-based methodologies to conduct human factors research to conduct performance basedassessment of diver ensembles and equipment.

4.1 CROM vs. Visual search

A comparison of cervical range of motion against the participants’ visual search times re-vealed a noticeable trend indicating that participants wearing the Fusion suit demonstratedthe least amount of CROM in three of the six movements evaluated (extension, left rota-tion, and right lateral) and was associated with the poorest task performance. This trendsupports the stated hypothesis and coincides with Alfano & Michel (1990), Toet (2007),and Toet’s (2008) conclusions regarding large head movements needed to compensate arestricted field of view. Additionally, this trend supports findings from Son et. al (2010),whom concluded that an increase in encumbrance would be associated with a decreasedtask performance.

In lieu of a semi-nude immersed condition, the wetsuit was intended to act as the in-waterbaseline condition due its reduced bulk, yet visual search performance was not superior tothe Kodiak condition despite consistently demonstrating greater CROM. This is in contractto a study on spinal manipulation therapy found that an improvement of next rotationby only 4 degrees significantly improved Fitt’s Task performance (Passmore et.al., 2010).Assessment of the subjective feedback questionnaires indicate that the wetsuit was scoredas requiring the least amount of mental and temporal demand, and effort. Meanwhile, itwas also scored as having the highest level of frustration. As the participants indicatedthat they were not as familiar with the wetsuit as the Kodiak and Fusions suits, a greateremphasis on conducting familiarization trials prior to the beginning of data collection shouldbe put into effect in future studies to account for learning effects. Additionally, it is possiblethat underwater Visual Search performance is based on multifactorial considerations as thediver must counter buoyancy and viscous moments and forces to manipulate the body in3D space. Thus differences in CROM may have been countered by other factors inherentto the suit condition.


4.2 Fine motor tasks vs whole body ROM

Overall, a greater horizontal shoulder flexion was associated with quicker rope tying times.Similarly, an increase in right sided trunk rotation resulted in an increase in the numberof weights transferred. This relationship of mobility and performance agrees with Coca et.al (2010) and their findings, whom concluded that a decrease in mobility can negativelyaffect performance. Interestingly, the relationship between rope tying performance and ROMsuggests a curvilinear trend such that performance appears to show increased rates ofimprovement above 90 degrees of shoulder flexion ROM. This type of relationship canbe useful for establishing minimum mobility requirements of dive suits.

The inverse relationship seen with the horizontal shoulder flexion versus the Nuts and Boltstask highlights an important distinction between gross motor and fine motor tasks. Whileit was hypothesized that encumbrance will decrease ROM and task performance, in thiscase, a greater ROM was associated with poorer fine motor task performance. Throughobservations, Nuts and Bolts task involved little movement of the upper limbs and thedivers remained in a relatively static position throughout the task. Meanwhile, the RopeTying task involved greater movement of the upper limbs to manipulate the rope andunravel the knots. This dissimilarity between fine and gross motor tasks may account forthe contrasting results. There appears to be a competing requirement for stability andflexibility which may operational considerations in specifying gear for specific missions.Greater ROM may facilitate tasks that involve greater movement at a joint; meanwhileincreased suit stiffness may stabilize the upper body/shoulder joint, aiding the performanceof a dexterity task that requires stability and precision. Furthermore, the Nuts and Boltstask was performed at a fixed station, meanwhile the Rope Tying task was, performed in anunconstrained space, requiring larger body movements to maintain stability. In their reviewof manual dexterity in open ocean underwater tasks, Hancock & Milner (1986) attributedthe stability of the work surface as an important contributor to increased task performance.Extending this conclusion to the current study, it is plausible that regional and restrictedROM may be a more suitable predictor of fine motor task performance when body stabilityis required (e.g. when working at a fixed work station).

4.3 Range of motion

A dynamic warm up was performed before each dryland and in-water ROM activity toincrease flexibility and to decrease the risk of injury. Roberts & Wilson (1999) showed thatholding a static stretch for 15 seconds resulted in greater ROM, as opposed to holding itfor 5 seconds. This reveals the magnitude in which stretching can alter mobility. All partic-ipants were instructed on appropriate static and dynamic stretches and warm up activities,however, the discipline to which they were performed was uneven. An insufficient or inap-propriate warm up could adversely affected measures which can greatly affect interpretationof the trend. Validity and reliability of range of motion and repeatability of joint angle dif-ferences may also be low due to a lack of participant motivation, difficulty following thestandardized technique, and difficulty in identifying landmarks. Physiological factors such


as muscle strength and endurance should be implemented in future studies comparing ROMagainst task performance, since some participants may be able to achieve the same distancewith more or less effort.

4.4 Suit differences

Overall, there was little, consistent discernibility between diving ensembles and task per-formance. This is not particularly surprising given the low number of participants andvariability of individual performance for each task. Understanding this variability is crucialto determining the minimal number of participants required to provide sufficient statisticalpower for detecting differences in performance (Guo et al., 2013).

A second factor which must be considered is the possibility that the tasks were not suffi-ciently challenging to the participants. This is exemplified by the subjective ratings of theNASA Task Load Index questionnaire, that revealed that participants reported these tasksto be low to moderately demanding. It is believed that by increasing the level of difficultyand challenging the working ranges and limits, discrimination between suit conditions wouldincrease. As the EDUG static tank is quite small, mobility tasks such as the visual searchor weight transfer tasks may not have been as challenging as if there were conducted in alarger body of water.

Finally, as a complete set of sizes of each dive suit were not available, participants wereaffected by the sizing and fitting of the suits. Moreover, participants indicated that theywere not as familiar with the wet suit as the Kodiak or Fusion. These suits are often custom-made or issued based on the individual’s anthropometric measures. As a result, borrowingof suits between participants was a common occurrence. Even though the participants mayhave successfully donned the suit, it does not necessarily reflect the manner in which the suitis intended to fit in local areas. Suits that are too large or too small could affect the validityof these measures. Future studies should include divers bring their own fitted or customsuit. Conversely, when evaluating non-issued garments, an operational definition of fit sothat dive suits can be issued according to a standardized methodology across participants.Once an optimal fit has been achieved, a familiarization trial should be held to ensure thatthe diver reaches a baseline level of task performance and familiarity with each suit.

4.5 Operations and task analysis

Underwater tasks performed in this study were based on an assessment of MCM taskselicited through interview with EDUG subject matter experts, review of RCN dive opera-tions manuals and external literature. In addition to limitations of time and scope, taskswere also selected based on suitability for implementation within the EDUG static divetank.

The Human Factors Test Plan (HFTP) for the Canadian Armed Forces diving program(Tack and Angel, 2015) clearly outlines the requirement for the development of operational


scenarios and the performance of function and task analysis to inform the operationalconditions and performance requirements of the diver and equipment to achieve missionsuccess. This process can then be used to define the personnel, logistics, environmentalconditions, dive mission scenarios/vignettes, tasks and performance metrics that wouldcontribute to the development of experimental test protocols.

The HFTP provides a number of valuable references to assist with the identification ofoperationally specific scenarios and associated divers tasks. Relevant scenarios can also beidentified through the support of the Clearance Diver Assessment Centre (CDAC). Addi-tionally, there has been a wealth of studies detailing mine counter measure task analysis andperformance standards commissioned by DRD/CFEME. In particular, a literature searchof DRDC/CFEME literature has identified 20 publications by Morrison and colleaguesof Shearwater Human Engineering (Annex C) on optimizing the performance and safetyof mine counter-measures diving. Unfortunately, these resources were not available to theauthors at the time of this study, however, a detailed review of these reports and the associ-ated recommendations should be valuable in the planning of future mine counter-measuresresearch as they provide valuable information on MCM task analysis, ergonomic recommen-dations and guidelines and proposed methods for evaluating MCM procedures using newtechnologies.

4.6 Environment

The EDUG static dive facility was a valuable asset for conducting a pilot evaluation ofthe ergonomic assessment methods and technologies employed in this study. In order toperform more comprehensive evaluations of complex operations requiring environmentalfactors (e.g. light, thermal, turbidity, current, or waves), mobility (e.g. transit, jackstaysearches or Pouncer operations) or team-based activities (e.g. zodiac based dive operations),it is essential that suitable facilities with qualified staff and environmental controls besourced.

Facility concepts, providing unique capabilities, for diving research are the Flume Tank atthe Fisheries and Marine Institute of Memorial University of Newfoundland (Figure 32),Helicopter Underwater Escape Training (HUET) facilities located at institutions such as:Memorial University, and Survival Systems Training and Survival Systems Limited in Dart-mouth, Nova Scotia. Human Sciences research personnel with extensive experience in mar-itime human factors research are available locally at Memorial (St. John’s) and Dalhousie(Halifax) Universities.

Memorial University’s Flume Tank is the world’s largest at 8 metres wide x 4 metres deepx 22.25 metres long and a water depth of 3–4 meters and can generate currents of up to2 knots full scale. Dyes can be added to the water to manipulate the turbidity of the water.A large viewing gallery provided experimenters with the ability to observe experimentaltrial in progress. Being a research facility, the flume facility is well instrumented for dataacquisition, underwater video and motion analysis.


Figure 32: Memorial University’s flume facility demonstrating use in diving operationsresearch. Copyright by the Fisheries and Marine Institute of Memorial University ofNewfoundland. Reprinted with permission from Paul Winger, 12 September 2017.

Environmental theaters and HUET trainers provide a unique opportunity to evaluate sur-face and subsurface operational scenarios. Memorial University, Survival Systems Limitedand Survival Systems Training offer facilities that can control multiple environmental con-ditions such as wind, wave height, fog, turbidity and lighting conditions. As an example,the Marine Aviation Survival Training facility (MAST) at Survival Systems Training is a


25m length x 14m width x 5m depth that employs a unique wave generator that can produce7 different wave patterns (including confused seas) and up to 1.8m in wave height.

As environmental theatres and HUET trainers are used for training purposes, they are wellsupported for ergonomics research by including large aprons for staging test equipmentand change room facilities. Simulated ships decks are provided to allow for jump platformsand marine emergency egress and ingress systems (e.g. slides, ladders, scramble net). TheMAST system includes a helicopter rescue hoist attached to a 7m static or dynamic mountto simulate helicopter extraction.

4.7 Quantification of system encumbrance and mobility4.7.1 Bulk

Performance metrics such as time to task completion and subjective ratings appear to be aneffective method to determine the net operational effectiveness of a diving system, however,it does not reveal the structural differences between difference equipment configurationswhich may give rise to these results. Typically, the encumbrance of clothing and equipmentis defined along three vectors – bulk, stiffness and weight.

Bulk may be determined by obtaining physical measures of the diver wearing dive ensemblesusing traditional methods such as measuring tape or calipers or 3D laser scanning techniquesto capture the dimension and shape data. Traditional methods have the advantage in that,accurate measurements of discrete locations can be obtained easily in both the laboratoryor field setting. Second, for looser fitting ensemble such as dry suits, the blousing of thematerial can be compressed to provide a more accurate assessment of the effective bulk(Kozey et al., 2005) that may be experienced while under hydrostatic pressure while diving.

3D scanning, provides detailed information regarding shape and bulk distribution of theequipment in relation to the diver’s body. A limitation of 3D scanning is that it does notpermit the compression of clothing and equipment, hence the shape and volumetric dataobtain may not be suitable for dive applications. Algorithms such as those developed forClothCap (Pons-Moll et al., 2017) provide a capability to model the draping of clothingof 3D body scans and predict its conformation to the body during motion. It would beinteresting to investigate the feasibility of applying these algorithms or methods to a divingscenario.

It is possible that some of these challenges can be mitigated by scanning divers wearingonly the hard, non-compressible equipment (e.g. mask, tanks, regulator) during scanning,but this would neglect the parameterization of the clothing and equipment ensemble as awhole. DRDC has conducted preliminary research to develop methods to quantify clothingand equipment bulk on dismounted soldiers (Jones et al., 2015), however its application tothe evaluation of bulk during dive operations has not been validated. The 3D scan datacollected as part of this study can be used to adapt these methods to account for compressiondue to hydrostatic pressure and better inform the quantification of dive ensemble bulk. This


could be accomplished by investigating additional 3D image capture techniques, such asphotogrammetry, to obtain objective data on how dive clothing shifts and conforms to thebody during water immersion. This could theoretically be modeled in a virtual environmentusing shape analysis or finite element modeling techniques to provide an objective predictionof immersed bulk and restriction to motion.

4.7.2 Ensemble Stiffness

Ensemble stiffness is a function of the material properties of the clothing and equipment,size and distribution of the equipment and its attachments and fit. The evaluation of en-semble stiffness is typically determined by a functional range of motion test as described inSection 2.4.4. Cervical range of motion measures were conducted on dry land as it was notdependent on balance or posture and it was assumed, rightly or wrongly, that there would belittle interaction between the medium (air or water) that the diver was placed in and taskperformance. Initial attempts at measuring CROM in-water proved unreliable, as it wasdifficult to fix the torso to isolate head motion. Admittedly, it would have been preferred toconduct all range of motion measures immersed. If this study were to be repeated, greatercare would be exercised in developing a technical and methodological solution to facilitateimmersed CROM measures. Range of motion of the torso, legs and arms is likely affectedby the fit or stiffness of the compressed diving clothing as well as the mass distribution ofthe equipment worn by the diver. For this reason, it was decided to perform the range ofmotion exercises in the static tank to account for hydrostatic pressure, buoyancy and thehydrodynamics of the water. While likely a more valid measure of ensemble stiffness, chal-lenges in maintaining posture and balance while performing the range of motion activitieswere noted. This can be resolved by providing a foot hold weighted or secured to the floorof the tank to provide stability while performing range of motion tasks. On the other hand,if one is interested in the functional effect of ensemble stiffness on balance and range ofmotion tasks, then an unrestrained posture is desirable.

4.7.3 Ensemble weight

Physical burden is typically identified as the mass and mass distribution of the physicalload carried by the warfighter. The effect of the load carried by diver affects performancevery differently as weight helps to counter the buoyancy of the diver and equipment, butcan also adversely affect mobility and stability if the load is excessive or unbalanced. Incertain circumstances, strategically placed weight may increase stability when working ona platform or ocean floor. Thus, gross dry weight of the diver may not necessarily bepredictive of underwater performance or encumbrance. It is recommended that a methodto determine immersed weight, buoyancy and moment of inertial/buoyancy be developedto develop acceptable standards and specifications for diving ensembles and equipment tooptimize diver performance.


4.7.4 Motion capture

Range of motion was quantified using 2D video analysis of high contrast markers placed onthe diver. This method is typically sufficient for simple movements that occur in one planesuch as those evaluated in this study. For more complex movements, such as those executedin underwater tasks, 3D motion analysis is required. This can be accomplished used twovideo cameras and a software tool such as ProAnalyst 3D (Xcitex, Woburn, MA). A secondoption is to use an optical tracking system built for underwater application. Qualisys (Qual-isys North America, Highland Park, IL) has successfully developed an underwater opticalmotion capture system that has been used for kinematic analysis of swimming (Olstad etal., 2012) (Figure 33). Currently, CETTs provides a ProAnalyst 3D software capability aswell as Qualisys Track Manager motion capture software. The Qualisys cameras availablethrough CETTs are not suitable for underwater application, however, the Fisheries andMarine Institute of Memorial University of Newfoundland possesses suitable cameras tofacilitate human factors studies in their Flume or HUET and Environmental Theatre. Datacaptured at Memorial University would be compatible with CETTs Qualisys software foranalysis.

Figure 33: Example of the Qualisys system adapted for underwater motion capture.Retrieved from https://www.flickr.com/photos/qualisys/ . Reprinted with

permission from Scott Coleman, Qualysis, NA, 11 September, 2017.

A major drawback with video and optical tracking systems to capture the motion of encum-bered individuals is that the tracking markers must be placed on the surface of clothing andequipment. As a result, the underlying motion of the diver may not be accurately tracked.


https://www.flickr.com/photos/qualisys/

This is particularly true when clothing and equipment is not tightly coupled to the diver’sbody. A third technology that may provide accurate body motion tracking are inertial mo-tion units (IMU’s) and have been validated in swimming application (De Magalhaes et al.,2014). IMU’s rely on inertial sensors and accelerometers to track relative motion and havebeen used successfully in biomechanical applications. As IMU’s are subject to magneticinterference, they can be problematic for use in ferrous environments such as vehicles orbuildings. Fortunately, dive equipment used for mine counter measures operations are devoidof ferrous or magnetic materials, making the use of IMU’s a very attractive option. CETTscurrently possesses a Synertial inertial motion capture system (Synertial U.S., Emeryville,CA), that could be adapted for diving applications by waterproofing the sensors and the ad-dition of a data logging unit to replace the BluetoothTM and WiFi communication systemsthat are typically employed.

4.7.5 Biomechanical modeling

While motion capture systems provide kinematic (motion) data, it is often important tounderstand the physical forces required by the diver to meet the challenges imposed bythe dive equipment, task and underwater environment. Modeling of these forces is typicallyachieved through biomechanical analysis using digital human modeling tools such as JACK(Siemens, Plano, TX), RAMSIS (Human Solutions of North America, Inc., Cary, NC) orVisual 3D (C-Motion, Germantown, MD), all of which are available through CETTs. Alimitation of these tools is the fact that that they do not account for the unique forcesand moments (e.g. hydrostatic pressure, buoyancy, and currents) experienced by divers.While few researchers have attempted to develop suitable models to assess underwaterbiomechanics (Seireg et. al, 1971), these models are not generally robust or available incommercial tools. Of interest, however is the SWUM (Swimming human Model) developedby a team led by Prof. Motomu Nakashima (2016).

SWUMsuit is a freely available software application that permits the analysis of four swim-ming strokes, accounting for fluid forces and body inertial. The output of this softwarecan be uploaded to AnyBody Modeling SystemTM (AnyBody Technology, Salem, MA) forbiomechanical analysis. An example of the output of the SWUMSuit model as representedin AnyBody Modeling SystemTM is provided in Figure 34.


Figure 34: Biomechanical analysis of the front crawl as represented by the SWUMsuitmodel using Anybody Modeling SystemTM. Retrieved from

http://www.swum.org/anybody_crawl.avi . Adapted with permission from the author,Motomu Nakashima, 15 September 2017.

Currently, SWUMsuit software does not account for the inclusion of dive equipment andencumbrance, however, it represents a potentially useful building block towards developinga virtual modeling tool for dive applications.

5 Conclusion

A pilot study, investigating the effect of encumbrance on diver underwater task perfor-mance, was conducted to evaluate the application of tools and methods developed in theComprehensive Ergonomics-based Tools and Techniques (CETTs) project to a diving sce-nario. Novel CETTs-based tools that were employed include 3D whole body scanning andoptical and video based motion capture. The central objective of this pilot study was to pro-vide preliminary information for the development of a standardized methodology to supportthe human factors evaluation dive clothing, equipment and platform.

Despite the low number of participants (5), trends were noted in task performance betweenthe different dive suit (encumbrance) conditions across. In certain cases encumbrance, asdefined as an decreased range of motion, were associated with poorer mobility, gross motortask performance, and visual search efficiency. Performance on a fine motor task appeared


http://www.swum.org/anybody_crawl.avi

to benefit by the most restrictive encumbrance condition, possibly due to providing greaterpostural stability in the underwater environment. Despite the challenges of quantifyingencumbrance and its effect on dive task performance, it was demonstrated that ergonomicmeasuring techniques can be adapted to the immersed environment. There are, however,several technical and procedural considerations that must be followed to ensure optimalquality of data:

• First, when conducting range of motion measurements, maintenance of proper postureand stability of the participant is paramount to ensure valid and repeatable measures.Buoyancy, fluid resistance and currents can interfere with the ability to perform therange of motion activities correctly. While ankle weights were provided to the partic-ipants in this study to improve stability, it is likely that a more robust solution bedevised.

• Second, range of motion was measured using video analysis to track markers placed onthe diver’s suit. As it is possible that the suit motion is not perfectly coupled to divermotion, errors in movement tracking may be introduced. The use of an inertial-basedmotion tracking system applied to the diver’s body would mitigate this concern.

• Finally, encumbrance may be described in terms of the bulk, weight and stiffness ofclothing and equipment. Hydrostatic pressure, buoyancy and hydrodynamic forcesinteract with a divers’ suit and equipment in such a way that the traditional, land-based paradigm of measuring encumbrance cannot be easily applied. Future researchshould focus on identifying and parameterizing key aspect of diver encumbrance thatare influence by the immersed environment.

The EDUG static tank provided a suitable environment for evaluating piloting this testmethodology, and may be adequate for evaluation of static tasks. To extend this capability,flume and environmental theatre facilities within Canada have been identified which providea state-of -the-art technical capabilities, ability to control environmental variables (e.g., seastate, turbidity and current), large water volume and safe operating conditions. Finally,as technical evaluation of diver performance can be costly and technically challenging, aOpenSource biomechanical modeling approach has been identified, having the potential tobe adapted to a diving scenario. This would allow the researcher to conduct computer-based “what if” simulations to better understand the interaction between the diver andtheir clothing and equipment and guide future research.


ReferencesAdams, P. S., & Keyserling, W. M. (1993). Three methods for measuring range ofmotion while wearing protective clothing: A comparative study. International Journalof Industrial Ergonomics, 12(3), 177–191.

Adams, P. S., Slocum, A. C., & Keyserling, W. M. (1994). A model for protectiveclothing effects on performance. International Journal of Clothing Science and Tech-nology, 6(4), 6–16.

Adams, P. S., & Keyserling, W. M. (1995). The effect of size and fabric weight ofprotective coveralls on range of gross body motions. American Industrial HygieneAssociation, 56(4), 333–340.

Alfano, P. L., & Michel, G. F. (1990). Restricting the field of view: Perceptual andperformance effects. Perceptual and motor skills, 70(1), 35–45.

Angel, H. & Tack, D. (2015). Human Factors Test Plan: Canadian Armed ForcesDiving Program. DRDC Contractor Report (unpublished)

Angel, H., & Tack, D. (2015). Human Factors Program Plan: Canadian Armed ForcesDiving Programme. DRDC Contractor Report (unpublished)

Arieli, R., Kerem, D., Gonen, A., Goldenberg, I., Shoshani, O., Daskalovic, Y.I., &Shupak, R. (1997). Thermal status of we-suited divers using closed circuit O2 appa-ratus in sea water of 17–18.5◦C. Eur J Appl Physiol (1997) 76: 69–74.

Bachrach, A. J., & Egstrom, G. H. (1974). Human engineering considerations in theevaluation of diving equipment. Naval Medical Research Inst Bethesda MD.

Bachrach, A. J., Egstrom, G. H., & Blackmun, S. M. (1975). Biomechanical analysisof the US Navy Mark V and Mark XII diving systems. Human Factors: The Journalof the Human Factors and Ergonomics Society, 17(4), 328–336.

Baddeley, A. D. (1966). Influence of depth on the manual dexterity of free divers:a comparison between open sea and pressure chamber testing. Journal of AppliedPsychology, 50(1), 81.

Baddeley, A., & Idzikowski, C. (1985). Anxiety, manual dexterity and diver perfor-mance. Ergonomics, 28(10), 1475–1482.

Banks, W. W. (1979). The effects of degraded visual and tactile information ondiver work performance. Human Factors: The Journal of the Human Factors andErgonomics Society, 21(4), 409–415.

Chaffin, D. B., Andersson, G., & Martin, B. J. (1984). Occupational biomechanics(pp. 14–52). New York: Wiley.


Coca, A., Williams, W. J., Roberge, R. J., & Powell, J. B. (2010). Effects of firefighter protective ensembles on mobility and performance. Applied ergonomics,41(4),636–641.

De Magalhaes, F.A, Vannozzi, G., Gatta, G. & Fantozzi, S. (2014) Wearable inertialsensors in swimming motion analysis: a systematic review. Journal of Sports Sciences.33(7):732:45.

Gaul, C. A., & Mekjavic, I. B. (1987). Helicopter pilot suits for offshore application Asurvey of thermal comfort and ergonomic design. Applied ergonomics, 18(2), 153–158.

Gerhardt, J., Cocciarella, L. & Lear, R. (2002). Practical guide to range of motionassessment. Chicago: American Medical Association. González-Alvarez, C., Subrama-nian, A., & Pardhan, S. (2007). Reaching and grasping with restricted peripheralvision. Ophthalmic and Physiological Optics,27(3), 265–274.

Guo, Y., Logan, H.L., Glueck, D.H., & Mueller, K.E. (2013). Selecting a sample size forstudies with repeated measures. BMC Medical Research Methodology 2013, 13:100.

Hancock, P. A., & Miller, E. K. (1986). Task performance under water: An evaluationof manual dexterity efficiency in the open ocean underwater environment. Appliedergonomics, 17(2), 143–147.

Hart, S. G. & Staveland, L. E. (1988). Development of NASA-TLX (Task Load Index):Results of empirical and theoretical research. In P. A. Hancock and N. Meshkati (Eds.)Human Mental Workload. Amsterdam: North Holland Press.

Hoffmann, E. R., & Chan, A. H. (2012). Underwater movement times with ongoingvisual control. Ergonomics, 55(12), 1513–1523.

Huck, J. (1988). Protective clothing systems: A technique for evaluating restriction ofwearer mobility. Applied ergonomics, 19(3), 185–190.

Jones, M.L.H, Kim, K.H., Keefe, A.A. Farrell, P.S.E., & Bossi, L.M. (2015). A PilotStudy of Three-Dimensional Equipped Anthropometry. Proceedings 19th TriennialCongress of the IEA, Melbourne 9–14 August 2015.

Kozey, J., Reilly, T., & Brooks, C. (2005). Personal protective equipment affectingfunctional anthropometric measurement. Occupational Ergonomics, 5(2), 121–129.

Margerum, S. E., Cowley, M., Harvill, L., Benson, E., & Rajulu, S. (2012, July).Evaluating Suit Fit Using Performance Degradation. In 42nd International Conferenceon Environmental Systems.

Nakashima, M., & Y. Motegi. (2007) Development of a full-body musculoskeletal sim-ulation for swimming. Proceedings of the 2007 International Symposium on computerSimulation in Biomechanics (ISCSB2007), 59–60.


Olstad, B. H., Zinner, C., Haakonsen, D., Cabri, J., & Kjendlie, P. L. (2012). 3Dautomatic motion tracking in water Wearable inertial sensors in swimming for mea-suring intra cyclic velocity variations in breast-stroke swimming. In R. Meeusen, J.Duchateau, B. Roelands, M. Klass, B. De Geus, S. Baudry, & E. Tsolakidis (Eds.),17th Annual Congress of the European College of Sport Science. Bruges: Vrije Uni-versiteit Brussel & Université Libre de Bruxelles.

Passmore, S.R., Burke, J.R., Good, C., Lyons, J.L. and Dunn, A.S. (2010). Spinalmanipulation impacts cervical spine movement and Fitts’ Task performance: A single-blind randomized before-after trial. J of Manipulative and Physiol Ther, 33(3), 189–92.

Pons-Moll, G., Pujades, S., Hu, S. and Black, M.J. (2017). ClothCap: Seamless 4Dclothing capture and retargeting. ACM Transactions on Graphics, 36(4), article 73,15pp.

Roberts, J. M., & Wilson, K. (1999). Effect of stretching duration on active andpassive range of motion in the lower extremity. British journal of sports medicine,33(4), 259–263.

Seireg, A., Baz, A. & Patel, D. (1971). Supportive forces on the human body duringunderwater activities. J. Biomechanics. 4, 23–30.

Son, S. Y., Xia, Y., & Tochihara, Y. (2010). Evaluation of the Effects of VariousClothing Conditions on Firefighter Mobility and the Validity of those MeasurementsMade. J. Hum Environ Syst 13(1), 15–24.

Toet, A., Jansen, S. E., & Delleman, N. J. (2007). Effects of field-of-view restrictionson speed and accuracy of manoeuvring 1, 2, 3. Perceptual and motor skills, 105(3f),1245–1256.

Toet, A., Kahrimanovic, M., & Dellerman, N.J. (2007). Locomotion through a complexenvironment with limited field of view. Perceptual and motor skills, 107, 811–826.

Uglene, W.V. (1998) Integration of the Canadian Forces’ clearance diver ensemble.Final Report – Phase 2 and 3. DCIEM-98-CR-42. Defence and Civil Institute ofEnvironmental Medicine.

Zander, J., & Morrison, J. (2008). Effects of pressure, cold and gloves on hand skintemperature and manual performance of divers. European journal of applied physiol-ogy, 104(2), 237–244.


Annex A Participant information sheet

The following is an information sheet provided to individual considering participating inthis study.

Purpose The purpose of this pilot study is to assess and understand all of thedimensions within diving which are operationally relevant, as well astheir relationship to encumbrance and task performance. The ultimategoal is to develop a methodology that can be implemented in futurestudies, and to provide future recommendations through acquisition.

Procedure Participants will undergo a series of dry land and under water tasks.Dry land tasks include 3D whole-body laser scanning in a semi-nude(shorts and sports bra for women) and each of three diving suitconditions while wearing an AGA dive mask and Compressed AirBreathing Apparatus (CABA) tanks. Visual field of view and neckrange of motion will also be measured. They will then enter an 8’ x 8’ x10’ dive tank and execute underwater whole-body range of motion, finemotor, gross motor, and field of view tasks. The range of motion taskwill be video captured for subsequent motion analysis. This sequence oftasks will be repeated for each of the 3 suit conditions, although the suitorder will be randomly assigned.

Voluntary Your participation is completely voluntary. You may end yourParticipation participation at any time, and you may refuse to conduct any task,

without repercussion or penalty.Time You will be required to complete the study over two days, takingInvolvement approximately 2 hours on day one and 5 hours on day two.Anonymity Participants will be assigned a unique alpha-numeric code as a means of

reference to their data. Data will be presented in averages across allmeasures in an effort to maintain confidentiality No information thatcould be used to infer the identity of the individual participants will bepublished. Video, photo or 3D scan image data will be retained for dataanalysis purposes and select images may be retained for archivalpurposes to inform future methodology development. These images willbe stored on a password protected hard drive and will only be accessibleby study investigators. Imagery that has been analyzed and not selectedfor archiving will be securely deleted from storage. The use of video orimagery for publications or presentation will only be considered whereexplicit permission is granted, as indicated by the participant in theDRDC Photo/Image Release Form.


Confidentiality The confidentiality of your responses is guaranteed. Defence Researchand Development Canadaresearchers are guided by, and adhere to,professional and ethical guidelines concerning behavioral research thatinvolves people. Only DRDC personnel will have access to theinformation from this study.Unless explicit permission is provided by the participant, photographicor video imagery will only be available to qualified personnel for dataanalysis. If permission of use is granted, image use will be restricted toDND authorized publications and presentations.

Risks and Many common diving risks will unlikely be encountered due to theMitigation shallow depth of the static dive tank, as well for its controlled

environment. This includes: barotrauma, decompression illness,hypothermia, and nitrogen narcosis. The risk of oxygen toxicity,hypercapnia, hypoxia, and drowning are still possible dangers of divingin the static tank. Despite these risks, they seldom occur due to theextensive education, training, and procedures enforced within divingoperations. Qualified military and professional divers are aware andthoroughly knowledgeable of the signs and symptoms of theaforementioned risks.It is possible to develop an infection if equipment and ensembles areshared. This will be avoided by ensuring each participant dives in theirown designated suits and all equipment is cleaned after use.Cramping of the hands due to the repetitive fine motor tasks may be anassociated risk. These tasks will be short in duration and participantswill be able to relax or stretch in between set ups for the next given task.Minor fatigue may be encountered after the repetitive gross motor taskthat involves swimming with a weight. The total swimming distanceand amount of weight carried will not be strenuous, especially for thesewell trained CAF divers. This same risk applies for the FOV task,although swimming distances are not remarkable. Fatigue could alsoarise after the ROM measures since they will be required to controltheir buoyancy and movement throughout all motions. Weighted bootswill be provided to assist participants with buoyancy control and toavoid unnecessary energy expenditure during this simple measure.Strains are a plausible risk during any of the ROM measures. Allparticipants will be instructed on proper form and technique for each ofthe movements preceding data collection. Participants will also receiveguidance and correction throughout the test to ensure proper form isattained. Movements will be encouraged to reach its fullest rangewithout applying severe strain.


Possible risks to the participant include minor skin irritation due to skincleaning and landmarking. The lasers used in this experiment areclassified as Class 1B and manufactured in compliance with theregulations of the Food and Drug Administration (United StatesDepartment of Health and Human Services), pertaining to laser safety.Maximum permissible exposure (MPE) for eyes or skin will not beexceeded throughout the course of the experiment.

Benefits This study will provide preliminary data for future studies evaluatingthe relationship between encumbrance and task performance in divingoperations. The benefit to the participant is the potential developmentof less constraining ensembles to permit additional safety and workefficiency.

Contact Infor- For any further questions or concerns about this project, or if you wishmation a copy of the final report, please contact Mr. Allan Keefe;

email: [email protected]

This project has been reviewed and approved by the DRDC HumanResearch Ethics Committee (Protocol 2015-005). If you would like tospeak with the Chair of this Board, please contact: Chair, DRDCHuman Research Ethics Committee (HREC); Phone number:416-635-2098; or [email protected]


[email protected]

Annex B NASA TLX and Encumbrance ratingquestionnaires

The following questionnaires were presented to all participants after completion of each ofthe three underwater task conditions to evaluate subjective ratings of physical and cognitiveworkload and the effect of suit encumbrance on task performance.

Figure B.1: NASA Task Load Index (TLX).


Table B.1: Subjective rating questionnaire on the effect of encumbrance on taskperformance.

Question Strongly Disagree Undecided Agree StronglyDisagree Agree1 2 3 4 5

1. The suit felt overlyrestrictive/bulky anddiminished my ability tomove through simpleranges of motion.2. The suit design wasrestrictive/bulky andprevented me fromperforming fine motortasks (e.g. nuts and bolts,rope tying) optimally.3. I had difficultyperforming the “grossmotor-transfer” task dueto the suits restrictive fit.4. I had difficultyperforming the “grossmotor-transfer” task dueto the suits configurationof bulk.5. As a means tocompensate for a restrictedfield of view while wearingthe AGA mask, large heador body movements wereneeded in this suit.6. My “In water- field ofview” performance couldhave improved if therestrictiveness of the suitwere to be minimized.7. My comfort was affectedin this suit due to itsrestrictiveness and theconfiguration of bulk.


Question Strongly Disagree Undecided Agree StronglyDisagree Agree1 2 3 4 5

8. Working carefully withsmall objects in front ofme was difficult and thusmy fine motor performancewas jeopardized due to thesuits restrictiveness.9. Maintaining a staticposition while workingcarefully with smallobjects was difficult.10. The level of bulk andrestrictiveness in this suitdid not affect myfunctional taskperformance.


Annex C Summary of DCIM/DRDC – Sponsoredreports on the Human Factors of MineCounter Measures Operations

The following is a summary of Mine Counter Measures Human Factors reports producedfor DCIEM/DRDC’s Experimental Diving Unit by Shearwater Engineering from 1997 to2006.

OPTIMIZING THE PERFORMANCE AND SAFETY OF MINECOUNTER-MEASURES DIVING

Phase 1

Morrison, J., Hamilton, K. and Zander, J. 1997. Optimizing the performance and safety ofmine countermeasures diving. Phase 1 Report. Prepared by Shearwater Human Engineer-ing for: Department of National Defence PWGSC Contract No. WW7711-5-7266; 210 pp,DCIEM Report 97-CR-43

Phase 2

Morrison, J., Hamilton, K. and Zander, J. 1998. Optimizing the performance and safetyof mine countermeasures diving. Phase 2, Part1 Report. Prepared by Shearwater HumanEngineering for: Department of National Defence PWGSC Contract No. WW7711-5-7266;33 pp, DRDC CR 2000-003

Morrison, J., Zander, J. and Hamilton, K. 1998. Optimizing the performance and safetyof mine countermeasures diving. Phase 2, part2: Information and display requirements forMCM Diving. Prepared by Shearwater Human Engineering for: Department of NationalDefence PWGSC Contract No. WW7711-5-7266; 35 pp, DRDC CR 2000-004

Morrison, J., Zander, J. and Hamilton, K. 1999. Optimizing the performance and safetyof mine countermeasures diving. Phase 2, part 3 Report. Prepared by Shearwater HumanEngineering for: Department of National Defence PWGSC Contract No. WW7711-5-7266;68 pp DRDC CR 2000-005.

Phase 3

Morrison, J.B. and Zander, J.K. 2005. Factors influencing manual performance in cold waterdiving. Prepared by Shearwater Human Engineering for: Department of National DefencePWGSC Contract No. WW7711-997606; 37 pp


Morrison, JB. and Zander, J.K. 2005. Determining the appropriate font size, and use ofcolour and contrast for underwater displays. Prepared by Shearwater Human Engineeringfor: Department of National Defence PWGSC Contract No. WW7711-997606; 48 pp

Morrison, JB. and Zander, J.K. 2005. Evaluation of head mounted and head down in-formation displays during simulated mine-countermeasures dives to 42 msw. Prepared byShearwater Human Engineering for: Department of National Defence PWGSC ContractNo. WW7711-997606; 52 pp

Morrison, J.B. and Zander, J.K. 2005. Investigation of button size and spacing for under-water controls. Prepared by Shearwater Human Engineering for: Department of NationalDefence PWGSC Contract No. WW7711-997606; 26 pp

Morrison, J.B. and Zander, J.K. 2005. Investigating the usability of underwater communi-cations systems. Prepared by Shearwater Human Engineering for: Department of NationalDefence PWGSC Contract No. WW7711-997606; 26 pp

Morrison, J.B. and Zander, J.K. 2005. The effect of pressure and time on information recall.Prepared by Shearwater Human Engineering for: Department of National Defence PWGSCContract No. WW7711-997606; 27 pp

Morrison, J.B. and Zander, J.K. 2005. The effects of exposure time, pressure and cold onhand skin temperature and manual performance when wearing 3-fingered gloves. Preparedby Shearwater Human Engineering for: Department of National Defence PWGSC ContractNo. WW7711-997606; 26 pp

PUBLICATIONS:

Ph.D. THESIS

Zander, J. 2005 Ergonomic guidelines for communication and display of information duringmine counter-measures diving operations. Ph.D., Simon Fraser University.

CONFERENCES (FULL PROCEEDINGS PUBLISHED)

Morrison, J.B. and Zander, J.K. 2005. Evaluation of the manual performance capabilitiesof workers wearing protective gloves. 36th Annual Conference, Association of CanadianErgonomists, August 2005, Halifax, NS

Morrison, J.B., Zander, J.K. and Cooper, J B. 2006. Investigation of the usability of diverunderwater communications systems. Proc. 37th Annual Conference, Association of Cana-dian Ergonomists, October 2006, Banff, AL


INTERNATIONAL ERGONOMICS ASSOCIATION (IEA) K.U. SMITH STU-DENT AWARD

Zander, J.K. 2006. Development and evaluation of ergonomic design guidelines for underwa-ter displays. International Ergonomics Association XVIth Triennial Congress, July 10-14,2006, Maastricht, Netherlands.

ABSTRACTED CONFERENCE PUBLICATIONS

Morrison, J.B., and Zander, J.K., 2003. Optimizing the performance and safety of minecountermeasures diving. Undersea and Hyperbaric Medical Society Annual Scientific Meet-ing, Quebec, Quebec, June 19-21, 2003.

Zander, J.K. and Morrison, J.B. 2003. The effects of neoprene gloves, pressure and coldwater on manual performance of divers. Undersea and Hyperbaric Medical Society AnnualScientific Meeting, Quebec, Quebec, June 19-21, 2003.

Zander, J.K. and Morrison, J.B. 2004. The Effects of Cold, Pressure and Gloves on ManualPerformance Capabilities of MCM Divers. Canadian Association of Underwater Scientists,Annual Meeting, October 21-24, University of British Columbia, Vancouver, BC

Zander JK, and Morrison J.B. 2005. Effects of exposure time, pressure and cold on hand skintemperature and manual performance when wearing 3-fingered neoprene gloves. Underseaand Hyperbaric Medical Society Annual Scientific Meeting, , Las Vegas, Nevada.

Zander J.K. Morrison J.B. and Eaton D. 2005. Evaluation of head mounted and head downinformation displays during simulated mine countermeasures dives to 42 msw. Underseaand Hyperbaric Medical Society Annual Scientific Meeting, Las Vegas, Nevada.


List of symbols/abbreviations/acronyms/initialisms

2D, 3D Two, Three DimensionBDR Battle Damage RepairCABA Compressed Air Breathing ApparatusCAF Canadian Armed ForcesCETTs Comprehensive Ergonomics-based Tools and TechniquesCFAS Canadian Forces Anthropometric SurveyCFEME Canadian Forces Environmental Medicine EstablishmentCROM Cervical Range of MotionDND Department of National DefenceDRDC Defence Research and Development CanadaDSTKIM Director Science and Technology Knowledge and Information ManagementEDUG Experimental Diving Undersea Group DV Dependent VariableEOD Explosive Ordnance DisposalFOV Field of ViewFP Force ProtectionHFPP Human Factors Program PlanHFTP Human Factors Test PlanHUET Helicopter Underwater Escape TrainingIV Independent VariableLED Light Emitting DiodeMAST Marine Aviation Survival TrainingMCM Mine Counter MeasuresPPE Personal Protection EquipmentRCN Royal Canadian NavyROM Range of MotionSOLAS Safety of Life at Sea


DOCUMENT CONTROL DATA*Security markings for the title, authors, abstract and keywords must be entered when the document is sensitive

1. ORIGINATOR (Name and address of the organization preparing thedocument. A DRDC Centre sponsoring a contractor’s report, or atasking agency, is entered in Section 8.)

DRDC – Toronto Research Centre1133 Sheppard Avenue West, TorontoON M3K 2C9, Canada

2a. SECURITY MARKING (Overall security marking ofthe document, including supplemental markings ifapplicable.)

CAN UNCLASSIFIED

2b. CONTROLLED GOODS

NON-CONTROLLED GOODSDMC A

3. TITLE (The document title and sub-title as indicated on the title page.)

Defining the relationship between encumbered ensembles and task performance indiving operations: A pilot study

4. AUTHORS (Last name, followed by initials – ranks, titles, etc. not to be used. Use semi-colon as delimiter)

Keefe, A.; Lim, T.

5. DATE OF PUBLICATION (Month and year of publication ofdocument.)

June 2018

6a. NO. OF PAGES (Totalpages, including Annexes,excluding DCD, coveringand verso pages.)

64

6b. NO. OF REFS (Totalcited in document.)

0

7. DOCUMENT CATEGORY (e.g., Scientific Report, Contract Report, Scientific Letter)

Scientific Report

8. SPONSORING CENTRE (The name and address of the department project or laboratory sponsoring the research anddevelopment.)

DRDC – Toronto Research Centre1133 Sheppard Avenue West, Toronto ON M3K 2C9, Canada

9a. PROJECT OR GRANT NO. (If appropriate, the applicableresearch and development project or grant number underwhich the document was written. Please specify whetherproject or grant.)

01cd

9b. CONTRACT NO. (If appropriate, the applicable contractnumber under which the document was written.)

10a. DRDC DOCUMENT NUMBER

DRDC-RDDC-2018-R16510b. OTHER DOCUMENT NO(s). (Any other numbers which may

be assigned this document either by the originator or by thesponsor.)

11a. FUTURE DISTRIBUTION WITHIN CANADA (Approval for further dissemination of the document. Security classification must alsobe considered.)

Public release

11b. FUTURE DISTRIBUTION OUTSIDE CANADA (Approval for further dissemination of the document. Security classification must alsobe considered.)

Public release

12. KEYWORDS, DESCRIPTORS or IDENTIFIERS (Use semi-colon as a delimiter.)

Diving; task performance; Comprehensive Ergonomics Tools and Techniques (CETTs); er-gonomics ; encumbrance

13. ABSTRACT/RÉSUMÉ (When available in the document, the French version of the abstract must be included here.)

DRDC’s Experimental Diving and Undersea Group (EDU) recognizes the requirement for a ca-pability to perform sound human factors and ergonomic research to support the specification, de-sign, development, and evaluation of diving clothing, equipment and platforms. In order to lever-age the emerging tools and capabilities available through DRDC’s Comprehensive Ergonomics-based Tools and Techniques (CETTs) capabilities, a pilot study was conducted to evaluate theeffect of ensemble encumbrance on diver underwater task performance.

Five Royal Canadian Navy Reserve divers were recruited from the HMCS York to participate inthis study. Each diver participated in three dive encumbrance conditions consisting of either aa) 6mm thick wetsuit, b) Fusion dry suit or c) Kodiak dry suit. An AGA full face dive mask andCompressed Air Breathing Apparatus (CABA) tanks were worn in each condition. Dive ensembleencumbrance was quantified by obtaining 3D volumetric scans, and measuring field of view andcervical range of motion. In-water assessment of ensemble encumbrance consisted of whole-body range of motion activities.

Performance tasks were based on simulated mine counter measures tasks and consisted of finemotor (rope tying and nuts/bolts assembly), gross motor (weight transfer) and a visual searchtasks. All in-water tasks were recorded using waterproof GoProTM cameras and evaluated ac-cording to time to task completion, NASA TLX response and subjective questionnaire. Despitethe low number of participants, results indicated trends that were consistent with task perfor-mance being adversely affected by encumbrance, as defined by a reduced range of motion. Theexception was the nuts and bolts task which appeared to benefit by the extra stability providedby a more restrictive suit. This research reinforces the importance of identifying objective mea-sures of encumbrance that are relevant to diver task performance. Challenges to quantifying diveensemble encumbrance in an underwater environment are identified and research gaps, tools,resources and facilities to support advanced diving human factors research are identified.

ABSTRACT/RÉSUMÉ (When available in the document, the French version of the abstract must be included here.)

Le Groupe de l’unité de plongée expérimentale (GPE) de RDDC reconnaît la nécessité de pos-séder la capacité d’effectuer des recherches approfondies sur les facteurs humains et l’ergonomiepour appuyer la description, la conception, la mise au point et l’évaluation des vêtements, del’équipement et des plateformes de plongée. Afin de tirer profit des capacités et des outils émer-gents qu’offre l’ensemble exhaustif d’outils et de techniques ergonomiques (EEOTE) de RDDC, ona mené une étude pilote dans le but d’évaluer l’effet de la charge exercée par l’équipement surl’efficacité des tâches effectuées sous l’eau par les plongeurs

On a recruté cinq plongeurs de la Marine royale canadienne (Réserve) parmi l’équipage du NCSMYork pour participer à l’étude. Chaque plongeur a pris part à trois exercices selon différentescharges de plongée, à savoir : a) une combinaison humide de 6 mm; b) une combinaison étancheFusion; c) une combinaison étanche Kodiak. Tous les plongeurs étaient équipés d’un masque facialintégral AGA et des bouteilles de plongée d’un appareil respiratoire à air comprimé (ARAC) lors dechaque exercice. La charge selon l’équipement de plongée a été quantifiée au moyen de balayagesvolumétriques et en mesurant le champ visuel et l’amplitude de mouvement cervical. L’évaluationsous l’eau comportait des exercices de mouvement d’amplitude de tout le corps.

L’exécution des tâches consistait en une simulation d’exercices de lutte contre les mines et com-portait des activités de motricité fine (nouage de cordes et assemblage par boulons et écrous), demotricité globale (transfert du poids) et de recherche visuelle. Toutes les tâches sous l’eau ont étéenregistrées au moyen de caméras étanches GoProTM et évaluées en fonction du délai pour lesmener à bien, de l’indice de charge de travail (ICT) de la NASA et d’un questionnaire subjectif. Mal-gré le nombre peu élevé de participants, les résultats ont montré des tendances qui correspondaientà l’efficacité des tâches sur lesquelles la charge exerce une influence défavorable, comme l’indiqueune amplitude de mouvement réduite. L’exception étant l’assemblage par boulons et écrous, celui-ci a semblé profiter d’une plus grande stabilité qu’apportait une combinaison plus contraignante.L’étude confirme l’importance d’établir des mesures objectives pour évaluer la charge pouvant avoirune incidence sur l’efficacité du travail des plongeurs. On a souligné la difficulté de déterminer lacharge globale de l’équipement de plongée dans un environnement sous-marin, ainsi que les la-cunes sur le plan de la recherche, des outils, des ressources et des installations pour appuyer desrecherches approfondies sur les facteurs humains relatifs à la plongée.


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